摘要
本文基于1个月、3个月和6个月时间尺度的SPI探究渭河流域的干旱特征,使用Mann-Kendall秩次检验法和重标极差分析法分析SPI序列的趋势性和持续性,识别干旱历时和烈度,计算“且”和“或”的联合重现期表征干旱风险,并分析其空间分布特征,得到如下结果:1)长时间尺度的SPI序列更加坦化,以渭河上游为例,6个月时间尺度较1个月时间尺度的识别结果,干旱场次减少了42场,而平均历时和平均烈度则分别增加了1.66和0.82;2)渭河上游干旱场次是五区中最小的,对应1个月、3个月和6个月时间尺度分别为76、47和34,历时和烈度是五个分区中最大的,北洛河和泾河呈相反的干旱特征,对应较大的干旱场次和较大的历时烈度;3)渭河干流1个月时间尺度的SPI和渭河中游6个月时间尺度的SPI存在显著下降趋势且有弱的正持续性,未来风险有增加的趋势;除严重干旱情景下的渭河中游、渭河下游和泾河外,其余类型、情景下短期干旱风险大于长期干旱风险。4)严重干旱情景下各区重现期差异较大,其中,1个月时间尺度下,渭河中游容易发生单变量较大的“或”类型干旱,短期干旱具有较大风险;3个月尺度下,渭河中游容易发生“且”类型干旱,一般干旱具有较大风险;6个月尺度下,泾河容易发生“且”类型的干旱,长期干旱具有较大风险。
In this paper,we used SPI with 1 month,3 months and 6 months timescale to explore the drought characteristics of the Wei River Basin.We analyze the trend and persistence of SPI time series by the Mann-Kendall rank test and Rescaled Range Analysis method.The results show that:1)As the time scale increases,the SPI time series attenuate.Taking the upper Wei River as example,the drought number of 6 months timescale has 42 that is less than the drought number of 3 months timescale;the average duration and severity have 1.66 and 0.82 which are larger than another respectively.2)In the upper Wei River,there are the smallest number of drought events,with corresponding timescales of 1 month,3 months and 6 months being 76,47 and 34,and larger drought duration and severity among the five subarea,while the Northern Luo River and Jing River show the opposite drought characteristics;except for the middle Wei River,the downstream of Wei River and the Jing river is under severe drought,and the risk of short-term drought is greater than that of long-term drought for all types and scenarios.3)The SPI with 1 month time scale of the whole Wei River Basin and the SPI with 6 months time scale of the middle Wei River have a significant downtrend and a weak positive persistence,which relveal that risks are likely to increase in the future.4)In severe drought situations,the return period varies greatly among different regions.Under the 1 month time scale,the middle Wei River tending to“or”type drought,a short term drought shows a greater risk;under the 3 month time scale,the middle Wei River tending to“and”type drought,a general term drought shows a greater risk;under the 6 month time scale,the Jing River tending to“and”type drought,a long term drought shows a greater risk.
作者
苟非洲
强文博
程玉婷
GOU Feizhou;QIANG Wenbo;CHENG Yuting(Shaanxi Water Affair Group Co.,LTD,Xi an 710004,China)
出处
《西安理工大学学报》
CAS
北大核心
2019年第4期443-451,共9页
Journal of Xi'an University of Technology
基金
国家自然科学基金资助项目(51709221)
